[PATCH] small optimization in __ip_conntrack_find()

[PATCH] small optimization in __ip_conntrack_find()

[Martin Josefsson]

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Hi,

Attached is a small optimization for __ip_conntrack_find().
The way I read the use of the LIST_FIND macro it seems that we are
calling hash_conntrack() for each iteration with the same inparameters.

My change calls it once before looping.

-- 
/Martin

Never argue with an idiot. They drag you down to their level, then beat
you with experience.

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--- linux-2.4.19-pre10/net/ipv4/netfilter/ip_conntrack_core.c.orig	Sat Jun  8 00:48:59 2002
+++ linux-2.4.19-pre10/net/ipv4/netfilter/ip_conntrack_core.c	Sat Jun  8 00:49:56 2002
@@ -292,9 +292,10 @@
 		    const struct ip_conntrack *ignored_conntrack)
 {
 	struct ip_conntrack_tuple_hash *h;
+	size_t hash = hash_conntrack(tuple);
 
 	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
-	h = LIST_FIND(&ip_conntrack_hash[hash_conntrack(tuple)],
+	h = LIST_FIND(&ip_conntrack_hash[hash],
 		      conntrack_tuple_cmp,
 		      struct ip_conntrack_tuple_hash *,
 		      tuple, ignored_conntrack);

Re: [PATCH] small optimization in __ip_conntrack_find()

[Harald Welte]

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On Sat, Jun 08, 2002 at 01:00:59AM +0200, Martin Josefsson wrote:
> Hi,
> 
> Attached is a small optimization for __ip_conntrack_find().
> The way I read the use of the LIST_FIND macro it seems that we are
> calling hash_conntrack() for each iteration with the same inparameters.

Thanks.  My assumption was that this is actually done by the optimization
code of gcc.  But from looking at the disassembled compiler output, there
is actually quite a difference between the old and the new code.

> My change calls it once before looping.

i'll put this into pending.

> /Martin


-- 
Live long and prosper
- Harald Welte / laforge@gnumonks.org               http://www.gnumonks.org/
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